Valve actuator

ABSTRACT

Spaced, single acting piston means are mounted for reciprocation within a housing, such pistons having interconnected therebetween and movable therewith a carrier means having cam surface means thereon. Fixed, rotatable bearing means are interposed between the housing and cam surface carrier to facilitate reciprocation of the cam surface carrier means within the housing in which it is supported. A cam follower means is provided for abutting the cam surface in the carrier, and crank means is connected therewith and is provided with means for connecting to a valve stem so that reciprocation of said cam surface carrier means in the housing causes the cam follower to move along said cam surface means and impart rotation to the crank arm means and the valve stem connected therewith. An indicator is connected with the cam follower to indicate externally of the housing the open or closed condition of the valve.

[451 Aug. 21, 1973 VALVE ACTUATOR Floyd L. Scott, Jr., 7922 WestglenDr., Houston, Tex.

[22] Filed: Mar. 3, 1971 [21] Appl. No.: 120,585

[76] Inventor:

[52] US. Cl. 92/5, 92/138 [51] Int. Cl. FOlb 9/00, FOlb 25/26, FOlb31/12 [58] Field of Search 92/31, 33, 5, 138; 74/55, 56, 89, 104, 107;251/25 D, 58; 123/56 C [56] References Cited UNITED STATES PATENTS2,229,545 l/1941 Beckstrom .123/56 C 3,610,568 10/1971 Duwe 1 251/582,998,805 9/1961 Usab 92/33 1,572,068 2/1926 Gould 92/31 2,883,1444/1959 Kendig. 92/31 X 2,401,466 6/1946 Davis 1 74/56 X 3,143,932 8/1964Lanman 92/31 3,198,539 8/1965 McMullen. 280/4317 3,274,901 9/1966 Yost92/31 3,338,140 8/1967 Sheesley 92/5 3,513,713 5/1970 Schumacher 74/55FOREIGN PATENTS OR APPLICATIONS 487,469 4/1918 France 92/138 PrimaryExaminer-Irwin G. Cohen Attorney-Jack W. Hayden [57] ABSTRACT Spaced,single acting piston means are mounted for reciprocation within ahousing, such pistons having interconnected therebetween and movabletherewith a carrier means having cam surface means thereon. Fixed,rotatable bearing means are interposed between the housing and camsurface carrier to facilitate reciprocation of the cam surface carriermeans within the housing in which it is supported.

A cam follower means is provided for abutting the cam surface in thecarrier, and crank means is connected therewith and is provided withmeans for connecting to a valve stem so that reciprocation of said camsurface carrier means in the housing causes the cam follower to movealong said cam surface means and impart rotation to the crank arm meansand the valve stem connected therewith. An indicator is connected withthe cam follower to indicate externally of the housing the open orclosed condition of the valve. 9

1 Claim, 6 Drawing Figures f/o /a A. Jca/z, (fr.

INVENTOR 4 BY Jade, W. Hagdew PAIENIEDMZI an 37533386 SHEET 3 OF 3/'/0ya Z. Jco/z, (/7:

INVENTOR BY Jada, Hagdew /ITTORNE Y VALVE ACTUATOR BACKGROUND OF THEINVENTION The field of the present invention relates to the valveactuator, and more particularly, a valve actuator for a ball, plug, orother rotatable type valve. Various devices have been proposed in theprior art and are in use at the present time for translating linearmovement of a valve actuator into rotary movement of a valve stem tomove the valve to open or closed position. A number of the devices inuse employ the scotch yoke, or a pin engaged between spaced projections,or a pin engaged in a helical slot.

Some of the prior art references which show such constructions includethe U.S. Fat. to R. W. Lanman, No. 3,143,932, issued on Aug. 11, 1964;the U.S. Pat. to J. M. Sheesley, No. 3,146,681, issued on Sept. 1, 1964;the U.S. Pat. to H. Ledeen et al., No. 3,261,266, issued on July 19,1966; and the U.S. Pat. to W. E. Heese, No. 3,152,520, issued on Oct.13, 1964. In these devices, a substantial portion of the energy of theactuator may be lost in the internal friction between the relativelymovable parts. Additionally, a helical type slot provides the same anglethroughout the entire length of the-slot. Such construction may giverise to undesirable characteristics in the starting and ending torque ofthe valve actuator.

SUMMARY OF THE INVENTION The present invention is directed to arelatively simple valve actuator construction which overcomes the aboveand other problems associated with the prior art.

Still another object of the present invention is to provide a valveactuator including housing means in which is supported movable pistonmeans having a carrier means extending therebetween in which is formedcam surface means for engaging with a cam follower upon movement of thecarrier within the housing which, in turn, rotates a crank arm which isprovided with means for connection with a valve stem for rotation of thevalve stem.

Yet a further object of the present invention is to provide a valveactuator incorporating a thin wedge which is adapted to be pushedbetween a plurality of rollers by a pressure force, some of the rollersbeing fixed, but rotatable, for supporting lateral thrust loads andspaced from other roller means which is attached to a crank for rotationthereof and for rotation of the valve stem adapted to be connectedtherewith when the wedge is moved in the space between the rollers.

Still another object of the present invention is to provide areciprocating valve actuator which is adapted to be moved laterallyrelative to the valve for rotation of the stem to open and close thevalve, the valve actuator including carrier means having a cam surfacearrangement formed thereon and a housing for supporting the carrier,there being rotatable bearing means for accommodating relative movementbetween the carrier and the housing and a cam follower for engaging withthe cam surface formed in the carrier to impart rotation to a crank anda valve stem adapted to be connected therewith upon movement of thecarrier in the housing.

Yet a further object of the present invention is to provide a valveactuator of relatively simple construction which substantially reducesthe friction between the moving parts so that a greater amount of theenergy input to the torque actuator is available for rotating a valvestem.

Still another object of the present invention is to provide a compactvalve actuator for rotating a valve stem to open and close a valve whichis constructed and arranged to provide high starting and high endingtorque.

Yet a further object of the present invention is to provide a valveactuator incorporating a cam surface formed in a carrier, the carrierbeing supported by bearing means in a housing for relative movementbetween the housing and the carrier.

Still a further object of the invention is to provide a valve actuatorincorporating a cam surface formed in a carrier, the carrier beingsupported by bearing means in a housing for relative movement betweenthe housing and the carrier, the carrier having piston means at each endthereof so that fluid pressure may be applied thereto for movement ofthe carrier.

Yet a further object of the present invention is to provide a valveactuator incorporating a cam surface formed in a carrier, the carrierbeing supported by bearing means in a housing for relative movementbetween the housing and the carrier incorporating barrier means so thata pressure force may be exterted thereagainst for movement of thecarrier whereupon a cam follower moves along the cam surface to rotate acrank and a valve stem connected therewith.

Still another object of the present invention is to provide a valveactuator incorporating a cam surface fonned in a carrier, the carrierbeing supported by bearing means in a housing for relative movementbetween the housing and the carrier incorporating barrier means so thata pressure force may be exerted thereagainst for movement of the carrierwhereupon a cam follower moves along the cam surface to rotate a crankand a valve stem connected therewith and indicator means for indicatingthe position of the cam follower relative to the cam surface as anindication of open or closed position of the valve.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevationillustrating the valve actuator of the present invention connected witha valve in a conduit;

FIG. 2 is a sectional view, partly in elevation, on the line 2-2 of FIG.1 illustrating structural details of the present invention;

FIG. 3 is a sectional view on the line 3-3 of FIG. 2, partly inelevation illustrating still further structural details of the presentinvention;

FIG. 4 is a perspective view illustrating the relationship of some ofthe components of the valve actuator of the present invention;

FIG. 5 is a perspective elevation showing an arrangement of the presentinvention for providing an additional torque required; and

FIG. 6 is a sectional view on the line 6-6 of FIG. 5 illustratingstructural details of the stacked housing arrangement shown in FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Attention is first directed toFIG. 1 of the drawings wherein the invention is referred to generally bythe numeral I0 and is shown as including housing means 9 which ismounted in any suitable manner on the valve housing 13. The valvehousing 13 is shown as having the flanges 14 and 15 connected therewithby the conduits 14a and 15a whereby the valve may be removablypositioned in the flow conduit referred to generally by the numeral 18.

The housing 9 in the form of the invention shown and described hereinhas cylindrical portions 17 carried on the center portion 11 and thecylindrical portions 17 each have end closure plates 16 which aresecured by any suitable means such as welding 19 or the like to thecylindrical end portions 17 of the housing 9. Carrier means 22 in theform of a plate-like member 23 is provided within the housing 9 and isconnected by any suitable means such as the brackets 24 and pins 25 tothe pistons 26 and 27 at each end thereof. The pistons 26 and 27 are ofa suitable diameter for fitting within the cylindrical housing portions17 and are provided with seal means 24 for sealing therebetween.

The carrier means 22 is provided with cam surface means referred .togenerally, at 28, and a cam follower means referred to generally by thenumeral 29 is provided for abutting the cam surface means uponreciprocation of the carrier means 22 and within the cylindricalportions 17 of the housing 9.

The cam follower means 29 is connected with the crank arm means 35, andthe crank arm means 35, as more clearly shown in FIG. 3 of the drawingshas secured thereto the stem 36 which is adapted to be connected with avalve stem 37 for imparting rotation thereto, as will be described ingreater detail hereinafter.

Suitable bearing means as referred to generally by the numeral 40 areprovided to support the carrier means 22 and absorb lateral thrustthereof during reciprocation within the housing 9.

The housing 9 may be constructed in any suitable manner, but as shown inthe drawings, the cylindrical portions 17 are provided withcircumferentially extending grooves 17a adjacent but spaced from eachend thereof to thereby provide the circumferentially extendingprojections 17b. The central portion of the housing 9 may be referred togenerally by the numeral 11 and includes hollow portions 11a and 11bhaving a cylindrical bore 11c extending partially in each end thereof. Acircumferential groove 11f is formed adjacent, but spaced from, the endof the cylindrical bore 110 and the projections 17b of each of thecylindrical portions 17 is adapted to fit therein. Thus, when the twoportions 11a and 11b are clamped around the ends of the cylindricalportions 17 as illustrated in FIG. 2 of the drawings, the cylindricalportions 17 and the two hollow central portions 110 and 11b fit togetherto form an integral housing 10. Any suitable means such as the bolts 113secured through the portions 11a and 1112 may be provided for lockingthe portions 11a and 11b together and in engagement with each of thecylindrical portions 17 to form the housing 9.

Of course, the cam follower 29, the carrier means 22, and pistons 26 and27 will be assembled to fit within the portions 11a and 11b before theportions 11a and 11b are secured together with housing portions 17 bythe bolts 113.

The cam surface means 28 is illustrated in the drawings as being in theform of a slot 28a of the lazy S type which in the preferred formcomprises mutually tangent circular arcs to provide desired starting andending torque characteristics in the valve actuator as will bedescribed. In some situations, where the valve is to be moved in onlyone direction, it can be appreciated that the cam surface means 28 maybe in the form of a half slot only so that only one cam surface isprovided in the valve actuator.

As better seen in FIG. 3, the cam follower 29 includes a bolt 29acarrying rotatable bearing means 29b positioned within an opening in theend of crank arm 35. Rotatable means 290 are provided on bolt 29a forriding against the cam surface means 28, and rotatable means 29d areprovided for fitting around the upper end of the bolt 29a and engagingwithin an opening in the crank arm 35a for a purpose to be described.

As shown in the drawings, the bearing means 40 comprise a plurality ofrotatable members 40a that are carried on the threaded shafts 40b withinthe housing portions 11a and 11b as more clearly illustrated in FIG. 3of the drawings. It will be noted that the bearing means 40 are arrangedwithin the central portion 11 of the housing 9 to engage the plate-likemember 23 on each side at spaced intervals therealong to absorb lateralthrust of the plate 23 during reciprocation of the platelike member 23within the housing 10.

The crank arm 35 is integrally formed with a shaft 36, and the shaft 36is provided with noncircular portions 36a which engage with similarnoncircular portions (not shown) in the opening 37a in the valve stem 37so that rotation of the shaft 36 is transmitted to the valve stem 37.

It will be noted that the end plates 16 are provided with fluid pressureinlets 16a and 17a, respectively, so that suitable fluid pressure may beconducted internally of the cylindrical portions 17 to act upon thepistons 26 or 27 and movethem and the carrier means 22 longitudinally ofthe housing 9.

For example, when the actuator is in the position as illustrated in FIG.2 and fluid pressure is conducted through the inlet 16a to act on thepiston means 26 and pressure relieved from the right-hand side of thepiston 27, the carrier means 22 will be forced longitudinally of thehousing 9 whereupon the cam follower 29 will move along the cam surface28 and cause the crank to rotate in a counterclockwise direction asviewed from the top in FIG. 2 of the drawings. When this occurs, theshaft 36 connected with the crank arm 35 will rotate and transmit suchrotation to the valve stem 37.

Likewise, when the cam follower 29 is in the position shown in FIG. 4 ofthe drawings and pressure is supplied to act upon the piston 27 in amanner to reciprocate the carrier means 22 in housing 9 to the left asviewed in FIG. 4 so that the crank arm 35 moves in a clockwise directionas does the shaft 36 and valve stem 37.

Some valve constructions require an extra force at the beginning and atthe end of the movable closed element movement to either rotate thevalve seat or to wipe the valve seat with closure element or to bringthe seat into tighter contact with the closure element.

Additionally, for some reasons because of misaligm ment, or for otherreasons, any valve is subject to the problem of being more difficult tomove towards opening or closing position in the last ten to fifteendegrees of travel.

It will be noted that the cam surface 28 of the present invention hasdifferent angles at different portions thereof. For examle, the startingangle of the cam surface 28 may vary anywhere frem 0 up to approximatelyone-half of the central angle of the cam surface 28. Similarly, theminimum central angle of the cam surface 28 should approximate And whilethe most preferred ratio between the center angle and the starting angleof the cam surface 28 is approximately four to one, this may be varieddepending upon the characteristics of the valve with which the presentactuator is to be employed. This, of course, determines theconfiguration of the cam surface 28. Thus, the present inventionprovides an actuator for a valve wherein the desired starting and endingtorque as well as intermediate torque between opening and closing of thevalve may be incorporated in the valve actuator with a minimum of effortto meet the torque requirement of the valve with which the actuator isto be used.

The cam surface 28 of the present invention may be considered as beingformed of aninfinite number of wedges, one of which is diagrammaticallyrepresented at 50 in FIG. 2 of drawings. As the carrier 22 moves, thethin wedge represented diagrammatically at 50 starts to move in thespace between the rotatable, but fixed, bearings or rollers 40 which areadjacent but spaced from the traveling roller represented by the camfollower 29, and this movement displaces the movable roller, or camfollower, 29 that is attached to the crank arm 35, and the crank arm 35is thereby forced to rotate, and this rotates shaft 36. Similarly, sincethe balance of the cam surface 28 may be considered an infinite numberof wedge surfaces arranged in juxtaposi tion so that the resultingsurface 28a as well as the sur face 28b is continuous and smooth, andcontinued movement of the carrier 22 will force the cam follower 29along cam surface 28 in a manner to avoid a bumpy, jerky operation ofthe valve actuator.

If desired, external adjustable stops may be provided on the end plates16 and 17 to limit rotation of the valve stem.

Additionally, as illustrated in dotted line at 51 of FIG. 2, suitablespring means may be employed to act against one of the piston means sothat if fluid pressure to the valve operator should fail, the springwill function to automatically move the operator so as to alwaysposition the valve in closed position, under some conditions. In lieu ofa spring, a pressure fluid energy accumulator might be connected withthe conduit at the opening 17a.

In FIG. 5 of the drawings, the present invention is illustrated asincorporating a plurality of valve actuators 10, each actuator employinga housing 9 including cylindrical end portions 17 and a central housingportion 11 constructed in a manner as previously described. It will benoted that the housings 9 are stacked vertically and suitable means suchas elongated bolts 60 are engaged so as to hold the portions 11a and 11bof each of the housings 9 interconnected.

The structure and function of this form of the invention is the same asthat previously described except the power of the valve actuator may beincreased by coupling the actuators together to thereby deliver moretorque. This is done by coupling the crank arms of the two together sothat they move in unison as fluid power is supplied through the ports16a and 17a to move the cam carrier 22 in each actuator. For example,the crank arm 35 of one of the pair of actuators is shown as beingconnected by its shaft 36 with a shaft 61 extending through 11a andintegrally connected with the crank arm 62. The crank 62 is, in turn,connected to the cam follower 29 that abuts against the cam surface 28and with which the crank arm 35 in the other or lowermost housing 9 isconnected. It is contemplated that the carrier means 22 of each of thevalve actuators shown in FIG. 6 will move in unison, and the resultingtorque will be applied through the output shaft 36 and to a valve stemconnected therewith.

In order to indicate the position of the valve, that is, either in openor closed position at all times, the crank arm 35a in both forms of theinvention shown is connected with the cam folower 29 as previouslydescribed. The arm 35a is, in turn, integrally connected with a shaft35b which extends out the top of the housing. The shaft 35b is providedwith a suitable pointer or indicator as referred to at 68 to indicatethe position of the cam follower 29 in relation to the cam surface 28,thus indicatingwhether the valve is in open or closed position.

The foregoing disclosure and description of the invention areillustrative and explanatory thereof, and various changes in the size,shape, and materials as well as in the details of the illustratedconstruction may be made without departing from the spirit of theinvention.

What is claimed is:

1. A valve actuator comprising:

a. a housing;

b. a plate having cam surface means therein reciprocably supported insaid housing;

6. piston means connected to each end of said plate and slidable withinsaid housing for reciprocation of said plate;

d. said cam surface means comprising an S-shaped slot formed by mutuallytangent circular arcs in the plane of said plate the ends of said slotextending in a generally axial direction along the path of pistonreciprocation;

e. rotatable bearing means between said housing and said plate andengaging said plate on each side at spaced intervals therealong toprovide lateral support for said plate;

f. cam follower means for abutting the slot in said plate;

g. crank arm means connected with said cam follower means;

h. means for connecting said crank arm means with a valve stem so thatreciprocation of said plate in said housing causes said cam follower tomove along the slot and rotate said crank arm means and valve stem; and

. indicator means connected with said crank arm means and supported insaid housing to indicate the position of said cam follower means inrelation to the slot.

Ik i

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,753,386 Dated August 21, 1973 Inventor(s) Floyd L. Scott, Jr.

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Col. 2, Line 12 insert: "present" before invention Signed and sealedthis 19th day of March 197A.

(SEAL) Attest:

EDWARD M.FLET CHER,JR. c. MnRsf iALL DANN Attesting Officer Commissionerof Patents FORM PO-1050 (10-69) USCOMM DC 603766359 a use GOVERNMENTPRINTING omce: Iss9 o-ass-au.

1. A valve acTuator comprising: a. a housing; b. a plate having camsurface means therein reciprocably supported in said housing; c. pistonmeans connected to each end of said plate and slidable within saidhousing for reciprocation of said plate; d. said cam surface meanscomprising an S-shaped slot formed by mutually tangent circular arcs inthe plane of said plate the ends of said slot extending in a generallyaxial direction along the path of piston reciprocation; e. rotatablebearing means between said housing and said plate and engaging saidplate on each side at spaced intervals therealong to provide lateralsupport for said plate; f. cam follower means for abutting the slot insaid plate; g. crank arm means connected with said cam follower means;h. means for connecting said crank arm means with a valve stem so thatreciprocation of said plate in said housing causes said cam follower tomove along the slot and rotate said crank arm means and valve stem; andi. indicator means connected with said crank arm means and supported insaid housing to indicate the position of said cam follower means inrelation to the slot.